The I-405/SR 167 interchange is one of the most heavily congested interchanges in the state. Today, drivers experience congestion in this area for up to eight hours each day.

Through this project, WSDOT will build a new flyover ramp connecting the HOT lanes on SR 167 to the carpool lanes on I-405 in Renton. This ramp is designed to improve traffic flow and safety at this critical interchange.

Why is WSDOT building this new flyover structure?
Traffic analyses show that this project will significantly decrease the hours of delay travelers experience in this area. The new connection will also reduce weaving at this interchange and on SR 167 and I-405, making collisions less likely.

The End Result
This critical flyover link may ultimately connect 25 miles of express toll lanes on I-405 with 15 miles of HOT lanes on SR 167, resulting in a 40-mile express toll lane system.

Needs & benefits

Congestion relief and safety: This project will improve traffic flow and decrease the likelihood of collisions by keeping traffic moving within the proposed express toll lane system. This highway-to-highway connection will solve weaving issues associated with drivers exiting the carpool or HOT lanes, merging onto I-405 or SR 167, and merging across traffic again to the HOT toll lanes. The result will be improved operations for both general purpose lanes and carpool or express toll lanes, providing benefits for all travelers, including transit.

Environment: This project will create better opportunities for drivers to use the SR 167 HOT lanes. Operating express toll lanes results in more reliable speeds and optimal lane performance, thus creating environmental benefits. By improving transit operations, increasing transit and carpool ridership, and improving traffic flow, we can decrease air pollution and greenhouse-gas emissions. This project will also install a noise wall, build storm water management facilities, and upgrade or replace stream crossings at I-405 and SR 167 to promote fish passage.

Economic stimulus: This project provides better transit access to affordable housing and employment centers. It also improves congestion, expanding freight mobility to the Green River Valley cities' warehousing and distribution centers. A major construction project like this one can create hundreds of jobs quickly across numerous trades.

Contact

The Washington State Department of Transportation is a public agency and is subject to the State of Washington’s Public Records Act (RCW 42.56). Therefore, public comments and questions may be made available to anyone requesting them for non-commercial purposes.